In the production of glass fiber products, such as glass fiber insulation and glass strands for reinforcement purposes, some scrap material is produced. This scrap comprises off-specification production, trimmings of insulation batts and the like.
This off-specification material has been disposed of in various ways but methods of reintroducing it into the process to recover the glass have been generally unsatisfactory. One principal difficulty arises due to a chemically-based binder or size which such scrap material has had applied to its surface during processing. When introduced directly into the glass batch, these surface coatings are difficult to burn off and their introduction into the molten glass affects the corrosion rate of the tank in which the molten glass is contained and changes the redox state of the glass. As a result of the latter, the radiant heat transfer characteristics of the furnace are adversely affected.
The method of this invention is directed to allowing the reintroduction of scrap glass into a glass melting furnace while avoiding these difficulties.